/*
 * Copyright 2002-2006 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.jtracc.util;

import java.util.*;

/**
 * Miscellaneous string utility methods. Mainly for internal use
 * within the framework; consider Jakarta's Commons Lang for a more
 * comprehensive suite of string utilities.
 * <p/>
 * <p>This class delivers some simple functionality that should really
 * be provided by the core Java String and StringBuffer classes, such
 * as the ability to replace all occurrences of a given substring in a
 * target string. It also provides easy-to-use methods to convert between
 * delimited strings, such as CSV strings, and collections and arrays.
 *
 * @author Rod Johnson
 * @author Juergen Hoeller
 * @author Keith Donald
 * @author Rob Harrop
 * @see org.apache.commons.lang.StringUtils
 * @since 16 April 2001
 */
public abstract class StringUtils
{

    private static final String FOLDER_SEPARATOR = "/";

    private static final String WINDOWS_FOLDER_SEPARATOR = "\\";

    private static final String TOP_PATH = "..";

    private static final String CURRENT_PATH = ".";

    private static final char EXTENSION_SEPARATOR = '.';

    //---------------------------------------------------------------------
    // General convenience methods for working with Strings
    //---------------------------------------------------------------------

    /**
     * Check if a String has length.
     * <p><pre>
     * StringUtils.hasLength(null) = false
     * StringUtils.hasLength("") = false
     * StringUtils.hasLength(" ") = true
     * StringUtils.hasLength("Hello") = true
     * </pre>
     *
     * @param str the String to check, may be <code>null</code>
     *
     * @return <code>true</code> if the String is not null and has length
     */
    public static boolean hasLength(String str)
    {
        return ( str != null && str.length() > 0 );
    }

    /**
     * Check if a String has text. More specifically, returns <code>true</code>
     * if the string not <code>null<code>, it's <code>length is > 0</code>, and
     * it has at least one non-whitespace character.
     * <p><pre>
     * StringUtils.hasText(null) = false
     * StringUtils.hasText("") = false
     * StringUtils.hasText(" ") = false
     * StringUtils.hasText("12345") = true
     * StringUtils.hasText(" 12345 ") = true
     * </pre>
     *
     * @param str the String to check, may be <code>null</code>
     *
     * @return <code>true</code> if the String is not null, length > 0,
     *         and not whitespace only
     *
     * @see java.lang.Character#isWhitespace
     */
    public static boolean hasText(String str)
    {
        int strLen;
        if (str == null || ( strLen = str.length() ) == 0)
        {
            return false;
        }
        for (int i = 0; i < strLen; i++)
        {
            if (!Character.isWhitespace( str.charAt( i ) ))
            {
                return true;
            }
        }
        return false;
    }

    /**
     * Trim leading and trailing whitespace from the given String.
     *
     * @param str the String to check
     *
     * @return the trimmed String
     *
     * @see java.lang.Character#isWhitespace
     */
    public static String trimWhitespace(String str)
    {
        if (!hasLength( str ))
        {
            return str;
        }
        StringBuffer buf = new StringBuffer( str );
        while (buf.length() > 0 && Character.isWhitespace( buf.charAt( 0 ) ))
        {
            buf.deleteCharAt( 0 );
        }
        while (buf.length() > 0 && Character.isWhitespace( buf.charAt( buf.length() - 1 ) ))
        {
            buf.deleteCharAt( buf.length() - 1 );
        }
        return buf.toString();
    }

    /**
     * Trim leading whitespace from the given String.
     *
     * @param str the String to check
     *
     * @return the trimmed String
     *
     * @see java.lang.Character#isWhitespace
     */
    public static String trimLeadingWhitespace(String str)
    {
        if (!hasLength( str ))
        {
            return str;
        }
        StringBuffer buf = new StringBuffer( str );
        while (buf.length() > 0 && Character.isWhitespace( buf.charAt( 0 ) ))
        {
            buf.deleteCharAt( 0 );
        }
        return buf.toString();
    }

    /**
     * Trim trailing whitespace from the given String.
     *
     * @param str the String to check
     *
     * @return the trimmed String
     *
     * @see java.lang.Character#isWhitespace
     */
    public static String trimTrailingWhitespace(String str)
    {
        if (!hasLength( str ))
        {
            return str;
        }
        StringBuffer buf = new StringBuffer( str );
        while (buf.length() > 0 && Character.isWhitespace( buf.charAt( buf.length() - 1 ) ))
        {
            buf.deleteCharAt( buf.length() - 1 );
        }
        return buf.toString();
    }

    /**
     * Trim <i>all</i> whitespace from the given String:
     * leading, trailing, and inbetween characters.
     *
     * @param str the String to check
     *
     * @return the trimmed String
     *
     * @see java.lang.Character#isWhitespace
     */
    public static String trimAllWhitespace(String str)
    {
        if (!hasLength( str ))
        {
            return str;
        }
        StringBuffer buf = new StringBuffer( str );
        int index = 0;
        while (buf.length() > index)
        {
            if (Character.isWhitespace( buf.charAt( index ) ))
            {
                buf.deleteCharAt( index );
            }
            else
            {
                index++;
            }
        }
        return buf.toString();
    }


    /**
     * Test if the given String starts with the specified prefix,
     * ignoring upper/lower case.
     *
     * @param str    the String to check
     * @param prefix the prefix to look for
     *
     * @see java.lang.String#startsWith
     */
    public static boolean startsWithIgnoreCase(String str, String prefix)
    {
        if (str == null || prefix == null)
        {
            return false;
        }
        if (str.startsWith( prefix ))
        {
            return true;
        }
        if (str.length() < prefix.length())
        {
            return false;
        }
        String lcStr = str.substring( 0, prefix.length() ).toLowerCase();
        String lcPrefix = prefix.toLowerCase();
        return lcStr.equals( lcPrefix );
    }

    /**
     * Test if the given String ends with the specified suffix,
     * ignoring upper/lower case.
     *
     * @param str    the String to check
     * @param suffix the suffix to look for
     *
     * @see java.lang.String#endsWith
     */
    public static boolean endsWithIgnoreCase(String str, String suffix)
    {
        if (str == null || suffix == null)
        {
            return false;
        }
        if (str.endsWith( suffix ))
        {
            return true;
        }
        if (str.length() < suffix.length())
        {
            return false;
        }

        String lcStr = str.substring( str.length() - suffix.length() ).toLowerCase();
        String lcSuffix = suffix.toLowerCase();
        return lcStr.equals( lcSuffix );
    }

    /**
     * Count the occurrences of the substring in string s.
     *
     * @param str string to search in. Return 0 if this is null.
     * @param sub string to search for. Return 0 if this is null.
     */
    public static int countOccurrencesOf(String str, String sub)
    {
        if (str == null || sub == null || str.length() == 0 || sub.length() == 0)
        {
            return 0;
        }
        int count = 0, pos = 0, idx = 0;
        while (( idx = str.indexOf( sub, pos ) ) != -1)
        {
            ++count;
            pos = idx + sub.length();
        }
        return count;
    }

    /**
     * Replace all occurences of a substring within a string with
     * another string.
     *
     * @param inString   String to examine
     * @param oldPattern String to replace
     * @param newPattern String to insert
     *
     * @return a String with the replacements
     */
    public static String replace(String inString, String oldPattern, String newPattern)
    {
        if (inString == null)
        {
            return null;
        }
        if (oldPattern == null || newPattern == null)
        {
            return inString;
        }

        StringBuffer sbuf = new StringBuffer();
        // output StringBuffer we'll build up
        int pos = 0; // our position in the old string
        int index = inString.indexOf( oldPattern );
        // the index of an occurrence we've found, or -1
        int patLen = oldPattern.length();
        while (index >= 0)
        {
            sbuf.append( inString.substring( pos, index ) );
            sbuf.append( newPattern );
            pos = index + patLen;
            index = inString.indexOf( oldPattern, pos );
        }
        sbuf.append( inString.substring( pos ) );

        // remember to append any characters to the right of a match
        return sbuf.toString();
    }

    /**
     * Delete all occurrences of the given substring.
     *
     * @param pattern the pattern to delete all occurrences of
     */
    public static String delete(String inString, String pattern)
    {
        return replace( inString, pattern, "" );
    }

    /**
     * Delete any character in a given string.
     *
     * @param charsToDelete a set of characters to delete.
     *                      E.g. "az\n" will delete 'a's, 'z's and new lines.
     */
    public static String deleteAny(String inString, String charsToDelete)
    {
        if (inString == null || charsToDelete == null)
        {
            return inString;
        }
        StringBuffer out = new StringBuffer();
        for (int i = 0; i < inString.length(); i++)
        {
            char c = inString.charAt( i );
            if (charsToDelete.indexOf( c ) == -1)
            {
                out.append( c );
            }
        }
        return out.toString();
    }

    //---------------------------------------------------------------------
    // Convenience methods for working with formatted Strings
    //---------------------------------------------------------------------

    /**
     * Quote the given String with single quotes.
     *
     * @param str the input String (e.g. "myString")
     *
     * @return the quoted String (e.g. "'myString'"),
     *         or <code>null<code> if the input was <code>null</code>
     */
    public static String quote(String str)
    {
        return ( str != null ? "'" + str + "'" : null );
    }

    /**
     * Turn the given Object into a String with single quotes
     * if it is a String; keeping the Object as-is else.
     *
     * @param obj the input Object (e.g. "myString")
     *
     * @return the quoted String (e.g. "'myString'"),
     *         or the input object as-is if not a String
     */
    public static Object quoteIfString(Object obj)
    {
        return ( obj instanceof String ? quote( (String) obj ) : obj );
    }

    /**
     * Unqualify a string qualified by a '.' dot character. For example,
     * "this.name.is.qualified", returns "qualified".
     *
     * @param qualifiedName the qualified name
     */
    public static String unqualify(String qualifiedName)
    {
        return unqualify( qualifiedName, '.' );
    }

    /**
     * Unqualify a string qualified by a separator character. For example,
     * "this:name:is:qualified" returns "qualified" if using a ':' separator.
     *
     * @param qualifiedName the qualified name
     * @param separator     the separator
     */
    public static String unqualify(String qualifiedName, char separator)
    {
        return qualifiedName.substring( qualifiedName.lastIndexOf( separator ) + 1 );
    }

    /**
     * Capitalize a <code>String</code>, changing the first letter to
     * upper case as per {@link Character#toUpperCase(char)}.
     * No other letters are changed.
     *
     * @param str the String to capitalize, may be <code>null</code>
     *
     * @return the capitalized String, <code>null</code> if null
     */
    public static String capitalize(String str)
    {
        return changeFirstCharacterCase( str, true );
    }

    /**
     * Uncapitalize a <code>String</code>, changing the first letter to
     * lower case as per {@link Character#toLowerCase(char)}.
     * No other letters are changed.
     *
     * @param str the String to uncapitalize, may be <code>null</code>
     *
     * @return the uncapitalized String, <code>null</code> if null
     */
    public static String uncapitalize(String str)
    {
        return changeFirstCharacterCase( str, false );
    }

    private static String changeFirstCharacterCase(String str, boolean capitalize)
    {
        if (str == null || str.length() == 0)
        {
            return str;
        }
        StringBuffer buf = new StringBuffer( str.length() );
        if (capitalize)
        {
            buf.append( Character.toUpperCase( str.charAt( 0 ) ) );
        }
        else
        {
            buf.append( Character.toLowerCase( str.charAt( 0 ) ) );
        }
        buf.append( str.substring( 1 ) );
        return buf.toString();
    }

    /**
     * Extract the filename from the given path,
     * e.g. "mypath/myfile.txt" -> "myfile.txt".
     *
     * @param path the file path (may be <code>null</code>)
     *
     * @return the extracted filename, or <code>null</code> if none
     */
    public static String getFilename(String path)
    {
        if (path == null)
        {
            return null;
        }
        int separatorIndex = path.lastIndexOf( FOLDER_SEPARATOR );
        return ( separatorIndex != -1 ? path.substring( separatorIndex + 1 ) : path );
    }

    /**
     * Extract the filename extension from the given path,
     * e.g. "mypath/myfile.txt" -> "txt".
     *
     * @param path the file path (may be <code>null</code>)
     *
     * @return the extracted filename extension, or <code>null</code> if none
     */
    public static String getFilenameExtension(String path)
    {
        if (path == null)
        {
            return null;
        }
        int sepIndex = path.lastIndexOf( EXTENSION_SEPARATOR );
        return ( sepIndex != -1 ? path.substring( sepIndex + 1 ) : null );
    }

    /**
     * Strip the filename extension from the given path,
     * e.g. "mypath/myfile.txt" -> "mypath/myfile".
     *
     * @param path the file path (may be <code>null</code>)
     *
     * @return the path with stripped filename extension,
     *         or <code>null</code> if none
     */
    public static String stripFilenameExtension(String path)
    {
        if (path == null)
        {
            return null;
        }
        int sepIndex = path.lastIndexOf( EXTENSION_SEPARATOR );
        return ( sepIndex != -1 ? path.substring( 0, sepIndex ) : path );
    }

    /**
     * Apply the given relative path to the given path,
     * assuming standard Java folder separation (i.e. "/" separators);
     *
     * @param path         the path to start from (usually a full file path)
     * @param relativePath the relative path to apply
     *                     (relative to the full file path above)
     *
     * @return the full file path that results from applying the relative path
     */
    public static String applyRelativePath(String path, String relativePath)
    {
        int separatorIndex = path.lastIndexOf( FOLDER_SEPARATOR );
        if (separatorIndex != -1)
        {
            String newPath = path.substring( 0, separatorIndex );
            if (!relativePath.startsWith( FOLDER_SEPARATOR ))
            {
                newPath += FOLDER_SEPARATOR;
            }
            return newPath + relativePath;
        }
        else
        {
            return relativePath;
        }
    }

    /**
     * Normalize the path by suppressing sequences like "path/.." and
     * inner simple dots.
     * <p>The result is convenient for path comparison. For other uses,
     * notice that Windows separators ("\") are replaced by simple slashes.
     *
     * @param path the original path
     *
     * @return the normalized path
     */
    public static String cleanPath(String path)
    {
        String pathToUse = replace( path, WINDOWS_FOLDER_SEPARATOR, FOLDER_SEPARATOR );

        // Strip prefix from path to analyze, to not treat it as part of the
        // first path element. This is necessary to correctly parse paths like
        // "file:core/../core/io/Resource.class", where the ".." should just
        // strip the first "core" directory while keeping the "file:" prefix.
        int prefixIndex = pathToUse.indexOf( ":" );
        String prefix = "";
        if (prefixIndex != -1)
        {
            prefix = pathToUse.substring( 0, prefixIndex + 1 );
            pathToUse = pathToUse.substring( prefixIndex + 1 );
        }

        String[] pathArray = delimitedListToStringArray( pathToUse, FOLDER_SEPARATOR );
        List pathElements = new LinkedList();
        int tops = 0;

        for (int i = pathArray.length - 1; i >= 0; i--)
        {
            if (CURRENT_PATH.equals( pathArray[i] ))
            {
                // Points to current directory - drop it.
            }
            else if (TOP_PATH.equals( pathArray[i] ))
            {
                // Registering top path found.
                tops++;
            }
            else
            {
                if (tops > 0)
                {
                    // Merging path element with corresponding to top path.
                    tops--;
                }
                else
                {
                    // Normal path element found.
                    pathElements.add( 0, pathArray[i] );
                }
            }
        }

        // Remaining top paths need to be retained.
        for (int i = 0; i < tops; i++)
        {
            pathElements.add( 0, TOP_PATH );
        }

        return prefix + collectionToDelimitedString( pathElements, FOLDER_SEPARATOR );
    }

    /**
     * Compare two paths after normalization of them.
     *
     * @param path1 First path for comparizon
     * @param path2 Second path for comparizon
     *
     * @return whether the two paths are equivalent after normalization
     */
    public static boolean pathEquals(String path1, String path2)
    {
        return cleanPath( path1 ).equals( cleanPath( path2 ) );
    }

    /**
     * Parse the given locale string into a <code>java.util.Locale</code>.
     * This is the inverse operation of Locale's <code>toString</code>.
     *
     * @param localeString the locale string, following
     *                     <code>java.util.Locale</code>'s toString format ("en", "en_UK", etc).
     *                     Also accepts spaces as separators, as alternative to underscores.
     *
     * @return a corresponding Locale instance
     */
    public static Locale parseLocaleString(String localeString)
    {
        String[] parts = tokenizeToStringArray( localeString, "_ ", false, false );
        String language = ( parts.length > 0 ? parts[0] : "" );
        String country = ( parts.length > 1 ? parts[1] : "" );
        String variant = ( parts.length > 2 ? parts[2] : "" );
        return ( language.length() > 0 ? new Locale( language, country, variant ) : null );
    }

    //---------------------------------------------------------------------
    // Convenience methods for working with String arrays
    //---------------------------------------------------------------------

    /**
     * Append the given String to the given String array, returning a new array
     * consisting of the input array contents plus the given String.
     *
     * @param array the array to append to (can be <code>null</code>)
     * @param str   the String to append
     *
     * @return the new array (never <code>null</code>)
     */
    public static String[] addStringToArray(String[] array, String str)
    {
        if (ObjectUtils.isEmpty( array ))
        {
            return new String[]{str};
        }
        String[] newArr = new String[array.length + 1];
        System.arraycopy( array, 0, newArr, 0, array.length );
        newArr[array.length] = str;
        return newArr;
    }

    /**
     * Concatenate the given String arrays into one,
     * with overlapping array elements included twice.
     * <p>The order of elements in the original arrays is preserved.
     *
     * @param array1 the first array (can be <code>null</code>)
     * @param array2 the second array (can be <code>null</code>)
     *
     * @return the new array (<code>null</code> if both given arrays were <code>null</code>)
     */
    public static String[] concatenateStringArrays(String[] array1, String[] array2)
    {
        if (ObjectUtils.isEmpty( array1 ))
        {
            return array2;
        }
        if (ObjectUtils.isEmpty( array2 ))
        {
            return array1;
        }
        String[] newArr = new String[array1.length + array2.length];
        System.arraycopy( array1, 0, newArr, 0, array1.length );
        System.arraycopy( array2, 0, newArr, array1.length, array2.length );
        return newArr;
    }

    /**
     * Merge the given String arrays into one, with overlapping
     * array elements only included once.
     * <p>The order of elements in the original arrays is preserved
     * (with the exception of overlapping elements, which are only
     * included on their first occurence).
     *
     * @param array1 the first array (can be <code>null</code>)
     * @param array2 the second array (can be <code>null</code>)
     *
     * @return the new array (<code>null</code> if both given arrays were <code>null</code>)
     */
    public static String[] mergeStringArrays(String[] array1, String[] array2)
    {
        if (ObjectUtils.isEmpty( array1 ))
        {
            return array2;
        }
        if (ObjectUtils.isEmpty( array2 ))
        {
            return array1;
        }
        List result = new ArrayList();
        result.addAll( Arrays.asList( array1 ) );
        for (int i = 0; i < array2.length; i++)
        {
            String str = array2[i];
            if (!result.contains( str ))
            {
                result.add( str );
            }
        }
        return toStringArray( result );
    }

    /**
     * Turn given source String array into sorted array.
     *
     * @param array the source array
     *
     * @return the sorted array (never <code>null</code>)
     */
    public static String[] sortStringArray(String[] array)
    {
        if (ObjectUtils.isEmpty( array ))
        {
            return new String[0];
        }
        Arrays.sort( array );
        return array;
    }

    /**
     * Copy the given Collection into a String array.
     * The Collection must contain String elements only.
     *
     * @param collection the Collection to copy
     *
     * @return the String array (<code>null</code> if the Collection
     *         was <code>null</code> as well)
     */
    public static String[] toStringArray(Collection collection)
    {
        if (collection == null)
        {
            return null;
        }
        return (String[]) collection.toArray( new String[collection.size()] );
    }

    /**
     * Remove duplicate Strings from the given array.
     * Also sorts the array, as it uses a TreeSet.
     *
     * @param array the String array
     *
     * @return an array without duplicates, in natural sort order
     */
    public static String[] removeDuplicateStrings(String[] array)
    {
        if (ObjectUtils.isEmpty( array ))
        {
            return array;
        }
        Set set = new TreeSet();
        for (int i = 0; i < array.length; i++)
        {
            set.add( array[i] );
        }
        return toStringArray( set );
    }

    /**
     * Split a String at the first occurrence of the delimiter.
     * Does not include the delimiter in the result.
     *
     * @param toSplit   the string to split
     * @param delimiter to split the string up with
     *
     * @return a two element array with index 0 being before the delimiter, and
     *         index 1 being after the delimiter (neither element includes the delimiter);
     *         or <code>null</code> if the delimiter wasn't found in the given input String
     */
    public static String[] split(String toSplit, String delimiter)
    {
        if (!hasLength( toSplit ) || !hasLength( delimiter ))
        {
            return null;
        }
        int offset = toSplit.indexOf( delimiter );
        if (offset < 0)
        {
            return null;
        }
        String beforeDelimiter = toSplit.substring( 0, offset );
        String afterDelimiter = toSplit.substring( offset + delimiter.length() );
        return new String[]{beforeDelimiter, afterDelimiter};
    }

    /**
     * Take an array Strings and split each element based on the given delimiter.
     * A <code>Properties</code> instance is then generated, with the left of the
     * delimiter providing the key, and the right of the delimiter providing the value.
     * <p>Will trim both the key and value before adding them to the
     * <code>Properties</code> instance.
     *
     * @param array     the array to process
     * @param delimiter to split each element using (typically the equals symbol)
     *
     * @return a <code>Properties</code> instance representing the array contents,
     *         or <code>null</code> if the array to process was null or empty
     */
    public static Properties splitArrayElementsIntoProperties(String[] array, String delimiter)
    {
        return splitArrayElementsIntoProperties( array, delimiter, null );
    }

    /**
     * Take an array Strings and split each element based on the given delimiter.
     * A <code>Properties</code> instance is then generated, with the left of the
     * delimiter providing the key, and the right of the delimiter providing the value.
     * <p>Will trim both the key and value before adding them to the
     * <code>Properties</code> instance.
     *
     * @param array         the array to process
     * @param delimiter     to split each element using (typically the equals symbol)
     * @param charsToDelete one or more characters to remove from each element
     *                      prior to attempting the split operation (typically the quotation mark
     *                      symbol), or <code>null</code> if no removal should occur
     *
     * @return a <code>Properties</code> instance representing the array contents,
     *         or <code>null</code> if the array to process was <code>null</code> or empty
     */
    public static Properties splitArrayElementsIntoProperties(
            String[] array, String delimiter, String charsToDelete)
    {

        if (ObjectUtils.isEmpty( array ))
        {
            return null;
        }
        Properties result = new Properties();
        for (int i = 0; i < array.length; i++)
        {
            String element = array[i];
            if (charsToDelete != null)
            {
                element = deleteAny( array[i], charsToDelete );
            }
            String[] splittedElement = split( element, delimiter );
            if (splittedElement == null)
            {
                continue;
            }
            result.setProperty( splittedElement[0].trim(), splittedElement[1].trim() );
        }
        return result;
    }

    /**
     * Tokenize the given String into a String array via a StringTokenizer.
     * Trims tokens and omits empty tokens.
     * <p>The given delimiters string is supposed to consist of any number of
     * delimiter characters. Each of those characters can be used to separate
     * tokens. A delimiter is always a single character; for multi-character
     * delimiters, consider using <code>delimitedListToStringArray</code>
     *
     * @param str        the String to tokenize
     * @param delimiters the delimiter characters, assembled as String
     *                   (each of those characters is individually considered as delimiter).
     *
     * @return an array of the tokens
     *
     * @see java.util.StringTokenizer
     * @see java.lang.String#trim
     * @see #delimitedListToStringArray
     */
    public static String[] tokenizeToStringArray(String str, String delimiters)
    {
        return tokenizeToStringArray( str, delimiters, true, true );
    }

    /**
     * Tokenize the given String into a String array via a StringTokenizer.
     * <p>The given delimiters string is supposed to consist of any number of
     * delimiter characters. Each of those characters can be used to separate
     * tokens. A delimiter is always a single character; for multi-character
     * delimiters, consider using <code>delimitedListToStringArray</code>
     *
     * @param str               the String to tokenize
     * @param delimiters        the delimiter characters, assembled as String
     *                          (each of those characters is individually considered as delimiter)
     * @param trimTokens        trim the tokens via String's <code>trim</code>
     * @param ignoreEmptyTokens omit empty tokens from the result array
     *                          (only applies to tokens that are empty after trimming; StringTokenizer
     *                          will not consider subsequent delimiters as token in the first place).
     *
     * @return an array of the tokens
     *
     * @see java.util.StringTokenizer
     * @see java.lang.String#trim
     * @see #delimitedListToStringArray
     */
    public static String[] tokenizeToStringArray(
            String str, String delimiters, boolean trimTokens, boolean ignoreEmptyTokens)
    {

        StringTokenizer st = new StringTokenizer( str, delimiters );
        List tokens = new ArrayList();
        while (st.hasMoreTokens())
        {
            String token = st.nextToken();
            if (trimTokens)
            {
                token = token.trim();
            }
            if (!ignoreEmptyTokens || token.length() > 0)
            {
                tokens.add( token );
            }
        }
        return toStringArray( tokens );
    }

    /**
     * Take a String which is a delimited list and convert it to a String array.
     * <p>A single delimiter can consists of more than one character: It will still
     * be considered as single delimiter string, rather than as bunch of potential
     * delimiter characters - in contrast to <code>tokenizeToStringArray</code>.
     *
     * @param str       the input String
     * @param delimiter the delimiter between elements (this is a single delimiter,
     *                  rather than a bunch individual delimiter characters)
     *
     * @return an array of the tokens in the list
     *
     * @see #tokenizeToStringArray
     */
    public static String[] delimitedListToStringArray(String str, String delimiter)
    {
        if (str == null)
        {
            return new String[0];
        }
        if (delimiter == null)
        {
            return new String[]{str};
        }
        List result = new ArrayList();
        if ("".equals( delimiter ))
        {
            for (int i = 0; i < str.length(); i++)
            {
                result.add( str.substring( i, i + 1 ) );
            }
        }
        else
        {
            int pos = 0;
            int delPos = 0;
            while (( delPos = str.indexOf( delimiter, pos ) ) != -1)
            {
                result.add( str.substring( pos, delPos ) );
                pos = delPos + delimiter.length();
            }
            if (str.length() > 0 && pos <= str.length())
            {
                // Add rest of String, but not in case of empty input.
                result.add( str.substring( pos ) );
            }
        }
        return toStringArray( result );
    }

    /**
     * Convert a CSV list into an array of Strings.
     *
     * @param str CSV list
     *
     * @return an array of Strings, or the empty array if s is null
     */
    public static String[] commaDelimitedListToStringArray(String str)
    {
        return delimitedListToStringArray( str, "," );
    }

    /**
     * Convenience method to convert a CSV string list to a set.
     * Note that this will suppress duplicates.
     *
     * @param str CSV String
     *
     * @return a Set of String entries in the list
     */
    public static Set commaDelimitedListToSet(String str)
    {
        Set set = new TreeSet();
        String[] tokens = commaDelimitedListToStringArray( str );
        for (int i = 0; i < tokens.length; i++)
        {
            set.add( tokens[i] );
        }
        return set;
    }

    /**
     * Convenience method to return a Collection as a delimited (e.g. CSV)
     * String. E.g. useful for <code>toString()</code> implementations.
     *
     * @param coll   Collection to display
     * @param delim  delimiter to use (probably a ",")
     * @param prefix string to start each element with
     * @param suffix string to end each element with
     */
    public static String collectionToDelimitedString(Collection coll, String delim, String prefix, String suffix)
    {
        if (CollectionUtils.isEmpty( coll ))
        {
            return "";
        }
        StringBuffer sb = new StringBuffer();
        Iterator it = coll.iterator();
        while (it.hasNext())
        {
            sb.append( prefix ).append( it.next() ).append( suffix );
            if (it.hasNext())
            {
                sb.append( delim );
            }
        }
        return sb.toString();
    }

    /**
     * Convenience method to return a Collection as a delimited (e.g. CSV)
     * String. E.g. useful for <code>toString()</code> implementations.
     *
     * @param coll  Collection to display
     * @param delim delimiter to use (probably a ",")
     */
    public static String collectionToDelimitedString(Collection coll, String delim)
    {
        return collectionToDelimitedString( coll, delim, "", "" );
    }

    /**
     * Convenience method to return a Collection as a CSV String.
     * E.g. useful for <code>toString()</code> implementations.
     *
     * @param coll Collection to display
     */
    public static String collectionToCommaDelimitedString(Collection coll)
    {
        return collectionToDelimitedString( coll, "," );
    }

    /**
     * Convenience method to return a String array as a delimited (e.g. CSV)
     * String. E.g. useful for <code>toString()</code> implementations.
     *
     * @param arr   array to display. Elements may be of any type (toString
     *              will be called on each element).
     * @param delim delimiter to use (probably a ",")
     */
    public static String arrayToDelimitedString(Object[] arr, String delim)
    {
        if (ObjectUtils.isEmpty( arr ))
        {
            return "";
        }
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < arr.length; i++)
        {
            if (i > 0)
            {
                sb.append( delim );
            }
            sb.append( arr[i] );
        }
        return sb.toString();
    }

    /**
     * Convenience method to return a String array as a CSV String.
     * E.g. useful for <code>toString()</code> implementations.
     *
     * @param arr array to display. Elements may be of any type (toString
     *            will be called on each element).
     */
    public static String arrayToCommaDelimitedString(Object[] arr)
    {
        return arrayToDelimitedString( arr, "," );
    }

}
